Field of the Invention
This invention relates to a swage fitting and a method of assembly thereof.
Description of Related Art
Swage fittings are known to connect tubes and pipes to each other to form fluid-tight connections in applications where a secure connection is critical, such as in aerospace, marine, petroleum and chemical industries. An axial swage tool is used to swage fittings to a tube.
During the swaging operation, the fitting is compressed axially by the swaging tool. The fitting's inner sleeve is compressed radially into the tube with a progressively diminished diameter. As a result, the tube is compressed into an hourglass shape with annular indentations formed in the tube, thereby securing it in the fitting with a metal-to-metal seal.
A typical swaged fitting includes a sleeve for receiving a tube and a swage ring sized to receive the sleeve. The swage ring includes an inner tapered surface that engages with a tapered outer surface of the sleeve prior to swaging. Some swage rings may be formed of a plurality of distinct pieces.
During swaging, the swage ring is moved axially in a forward direction over the sleeve such that interaction of the tapered surfaces on the ring and sleeve deforms the sleeve and tube inwardly to form a swaged connection between them. The swage ring and sleeve are thus permanently swaged to the tube.
Other known end fittings for a tube include a male end fitting assembly used with a female fitting. The female end fitting includes a sleeve placed over a tube and a nut. The male fitting has a threaded outer surface for screwing into the nut, and a conical inner surface for receiving the tubing and the sleeve of the female end fitting assembly. As the nut is advanced axially, the sleeve is mated to the adapter fitting. The prior art suffers from the problem that these swage fittings have undesirable mass compared to the same length of tubing.